Pizzeria Libretto currently does offer the best Napoli style pizza in the city. Every time we decide to go I get excited, but usually find I am disappointed pretty quickly when I am there.
First, the dough is great. And that's what you have to start with with these pizzas. The cheese is always quite good too on the margarita. However, I get majorly disappointed by the tomatoes. They never taste sweet like other San Marzano tomatoes I have experienced on these kinds of pizzas.
I also wouldn't recommend getting the buffalo mozzarella. It's not better enough here to make it worth the extra money.
The servers are usually nice (though this has not always been true the 7-8 times I've been), but the pizzas are always insanely slow to arrive!! I never understand why either, since the place isn't full and the pizzas are meant to cook in under 2 minutes or less...?
I will say if you can get in for their lunch specials with the salad and dessert, do it. The salad and beet option are both winners, and the biscotti is quite good here too.